"The course that we'll continue will be the same trend that he [Larijani] has pursued in this period of time."

Javier Solana, the EU foreign policy chief, described the meeting as "constructive" and said more talks would probably be held by the end of November.

The talks addressed Iran's work with the UN nuclear watchdog, the International Atomic Energy Agency (IAEA), which is investigating Iran's past nuclear activities, as well as other nuclear issues, said Larijani.

Hardening stance?

The resignation of Larijani, viewed as moderate compared with Mahmoud Ahmadinejad, the president, and the two often clashed over how to negotiate with the world on the nuclear issue.

Larijani was seen as committed to a diplomatic solution over Iran's nuclear programme, while Ahmadinejad is seen as not favouring talks with the West.

Jalili, whose new official title as secretary of the Supreme Security Council makes him the chief nuclear negotiator, is an Ahmadinejad loyalist.

The president has said Iran would not negotiate over its "nuclear rights" and that he believed the nuclear issue was over.

However, he also said this month that the government was prepared to answer questions from the IAEA.

'Not one iota'

On Tuesday, he was quoted as saying by Iranian state television during a trip to Armenia: "We are in favour of talks but we will not negotiate with anyone about our right to nuclear technology.

"Iran will not retreat one iota," he said.

Larijani was dismissive of speculation about his resignation as a possible signal that Tehran has decided to take a harder line, portraying it as normal generational change.

"The point is our country is a democracy, there is rotation and circulation of forces and powers," he said. "Jalili is a friend of mine, seven or eight years younger, energetic... He will continue doing the work. I will have my full support directed at him."

Larijani also expressed support for Ahmadinejad and downplayed alleged differences with him.

The Rome talks had been scheduled before Larijani's resignation was announced, and Solana's spokeswoman, Cristina Gallach, said that Larijani was "very engaged".

She cited uranium enrichment as one of the main issues that needed clarification.

Iran's refusal to halt work that can be used to make fuel for power plants or, if it wants, material for warheads, has already prompted two sets of UN Security Council sanctions.

World powers have agreed to delay further penalties on Iran at least until November to see if Iran co-operates with IAEA inspectors, and to await a report by Solana.

Solana's mandate is to explore the scope for entering formal negotiations with Iran on international demands that it halt sensitive nuclear activities.

The West fears Iran's nuclear programme could be aimed at making bombs but Tehran says it just wants to produce electricity so it can keep its oil and gas for export.

George Bush, the US president, on Tuesday argued for a missile defence shield in Europe against Iranian missiles.

"Iran is pursuing the technology that could be used to produce nuclear weapons and ballistic missiles of increasing range that could deliver them," he said.

"We need to take it seriously now. Today we have no way to defend Europe against the emerging Iranian threat. And so we must deploy a missile defence system there that can."